Certain manufacturing processes require the use of liquid chemicals such as acids, solvents, bases, photoresists, CMP slurries, dopants, inorganic, organic and biological solutions, pharmaceuticals, and radioactive chemicals. Often, these processes require a specific liquid chemical for each particular process. Furthermore, each process may require a specific liquid chemical at various stages of the process. Storage and dispensing systems in many instances are arranged to allow alternative containers to be used to deliver liquid chemicals to a manufacturing process at a specified time. Consequently, manufacturing personnel need to change the liquid chemical being used for the particular process at the specified time so that the system delivers the correct liquid chemical to the manufacturing process. It is critical that the proper liquid chemical be installed into the systems for the particular process. If the incorrect liquid chemical is installed for a particular process, personnel may be put at risk. Furthermore, equipment and the articles under manufacture may be severely damaged or even rendered useless for their intended functions.
Prior art systems have attempted to utilize unique pump connectors that will only fit with a correct container. Each container has a unique configuration based on the liquid chemical contained therein. The intention is that only the correct chemical can be used in any particular manufacturing process, because the process will dictate a unique pump connection and a corresponding container with the correct chemical liquid. One example of such a system is disclosed in Osgar et al., “Liquid Chemical Dispensing System With Sensor,” U.S. Pat. No. 5,875,921. The Osgar system uses physical configurations, called key codes, to prevent accidental dispensing of an improper liquid from a container. Both the container and a connector have unique key code configurations. The connector must have the same key code configuration as the container for the connector to be properly coupled with the container. The Osgar system also employs a sensor that senses proper coupling of the connector to the container. When the sensor senses a proper coupling of the connector to the container, a pump is enabled. When the container and the connector are not properly coupled, the pump is disabled.
Some prior art systems, however, do allow the pump connectors to be partially connected to the incorrect chemicals such that pumping can take place even though the connection is not proper. In addition, personnel still can attach the wrong chemical to the wrong process or at the wrong time. Such incorrect connections can be dangerous to personnel and have caused millions of dollars of damage to equipment and to articles of manufacture. A system that provides a reliable connection between the correct chemical and the correct process, and enables tracking of incorrect connection attempts by personnel would be a useful improvement over the prior systems.